The Evolution of Consciousness

Excerpted from book From Science to God

I have argued that the faculty of consciousness is present in all beings.(See Are All Creatures Conscious). Consciousness is not something that emerged with human beings, or with vertebrates, or at any particular stage of biological evolution. What emerged over the course of evolution was not the faculty of consciousness, but the various qualities and dimensions of conscious experience–the contents of consciousness.

The earliest living organisms, bacteria and algae, had no sensory organs and detected only the most general characteristics and changes in their environment. Their experience might be likened to an extremely dim, almost imperceptible hint of light on an otherwise dark screen–virtually nothing compared to the richness and detail of human experience.

With the evolution of multicellular organisms came the emergence of specific senses, enhancing the quality of consciousness. In order to process this information and distribute it to other parts of the organism, nervous systems evolved, integrating the different sensory modalities into a single picture of the world.

As brains grew in complexity, new features were added to the image appearing in consciousness. With mammals the limbic system appeared, bringing feelings such as fear, arousal, and emotional bonding. With time, the mammalian the brain grew yet more complex, developing a new structure around it, the cerebral cortex. With this came better memory, focused attention, greater intention, and imagination.

With human beings another new capacity emerged–speech. And with this, the evolution of consciousness took a huge leap forward.

We could use words to communicate experiences with each other. Our awareness of the world was no longer limited to what our senses told us; we could know of events occurring in other places and at other times. We could learn from each other’s experiences, and so begin to accumulate a collective body of knowledge about the world.

Most significantly, we began to use language internally. Hearing words in our minds without actually saying them, allowed us to talk to ourselves. An entirely new dimension had been added to our consciousness–verbal thought. We could form concepts, entertain ideas, appreciate patterns in events, apply reason, and begin to understand the universe in which we found ourselves.

Then came the most important leap of all. Not only could we reflect upon the nature of the world around us, we could also reflect upon thinking itself. We became self-aware–aware of our own awareness. This opened the door to a whole new arena of development. We could begin to explore the inner world of the mind and, ultimately, delve into the nature of consciousness itself.

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